hergom SAJA 7 Instruction Book page 17

If the distance of the location of your cooker in relation to the central point of
the chimney is greater than that provided by the elbow joint (16 cm.), you can
use these extension collars (Hergóm supplies one collar per elbow joint).
Each collar provides an additional length of 7 cm. (See figure below)
The securing system is carried out in the same manner as the elbow joint.
DRAUGHT REGISTER
INSTALLATION OF THE DRAUGHT REGULATION VENT AND CLEANING
REGISTER ON THE OUTLET OF COMPLETE RANGE COOKERS.
Although complete range cookers are fitted with a system to control the precise
inlet of air for combustion, mainly for installations with a high chimney draught
caused by their height (over 5 metres), good construction, insulation, etc., it is wise
to place a register on the wall at the outlet of the cooker that will help towards a
more precise control of the chimney depression and, as a result, the calorific
power and expense of fuel.
This register, due to its unique design, allows not only for the draught to be
controlled but also for easier cleaning, due to the window for access to the inside
of the chimney, thus leading to better operating.
This register is easily fitted, following the instruction indicated in the attached
diagram.
It is VERY IMPORTANT for the draught shut-off plate not to close off the
passage of smoke completely, given that this may cause an accident by not
allowing for them to evacuate if closed completely.
The free safety section for the circulation of smoke must not be below 20%
the gap in the cast iron frame. Where necessary, cut the "DRAUGHT CUT-
OFF" plate to keep the free space recommended.
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